Plate type burner

ABSTRACT

A plate type burner includes a burner main body and burning plates mounted on an opened surface of the burner main body. A flange portion enclosing the opened surface is formed on an upper surface of the burner main body. The outer edge of each of the burning plates is placed on the flange portion with a sheet of packing interposed therebetween. The outer edge of each of the burning plates is pressed downward by a pressing plate. The flange portion is shaped in a stepped shape in which the inner part thereof on the side of the opened surface is formed lower than the outer part thereof. Then, the packing is compressed between the stepped part of the flange portion, the stepped part formed in the vertical direction, and the end face of the outer edge of each of the burning plates. Each of the burning plates is pressed to the inner side in the arrangement direction by the reaction force of the compression of the packing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a plate type burner including abox-shaped burner main body with an upper surface formed as an opensurface and burning plates mounted on the open surface of the burnermain body for burning a mixture gas by jetting the mixture gas from theinside of the burner main body to the outside thereof through amultiplicity of burner ports formed in the burning plates.

2. Description of the Related Art

Conventionally, as this type of plate type burner, the following one isknown (see, for example, Japanese Patent Application Laid-OpenPublication No. 2004-333099). That is, a flange portion enclosing theopen surface is formed on the upper surface of the burner main body; theouter edge of each of the burning plates is placed on the flange portionwith an annular sheet of packing put between them; and the sealingproperty between the burner main body and each of the burning plates issecured by pressing the outer edge of each of the burning platesdownward with a pressing plate to compress the packing.

Moreover, a plurality of burning plates is sometimes mounted by beingarranged on the open surface of the burner main body in such a platetype burner. In this case, in order to prevent gas leakage from thebutting parts of the burning plates, it becomes necessary to press theburning plates situated on both the outer sides in the arrangementdirection of the plurality of burning plates to the inner side in thearrangement direction with spring members. Consequently, the number ofparts increases and an increase in cost is brought about.

SUMMARY

In view of the above-mentioned problems, it is an advantage of thepresent invention to provide a low cost plate type burner capable ofpreventing any gas leakage from butting (butt joint) parts of burningplates without using any spring members.

According to an aspect of the present invention, there is provided aplate type burner, comprising: a burner main body shaped in a box withan upper surface thereof being formed as an open surface; and aplurality of burning plates mounted side by side in the open surface sothat a mixture gas is jetted for combustion from inside the burner mainbody through a multiplicity of burner ports formed in each of theburning plates. The burner main body has formed on the upper surfacethereof a flange portion in a manner to enclose the open surface. Eachof the burning plates is placed on the flange portion at an outer edgethereof with an annular packing being interposed therebetween such that,by pressing downward the outer edge of each of the burning plates by apressing plate to compress the packing, sealing property is securedbetween the burner main body and each of the burning plates. The flangeportion is formed in a stepped shape with an inner part on a side of theopen surface being lower than an outer part. A vertical stepped partbetween the inner part and the outer part is formed at a position wherea gap narrower than a thickness of the packing in a free state thereofis produced between an end face of the outer edge of each of the burningplates and the stepped part. The packing is formed in a size largeenough to project from the inner part of the flange portion to the outerpart thereof beyond the stepped part.

According to the aspect of the present invention, when the outer edge ofeach of the burning plates is pressed downward with the pressing plate,the packing is compressed between the inner part of the flange portionand the under surface of each of the burning plates. Furthermore, alsobetween the end face of the outer edge of each of the burning plates andthe stepped part of the flange portion, the packing is compressed, andconsequently the sealing property between the burner main body and eachof the burning plates becomes good. Moreover, the burning platessituated on both the outer sides in the arrangement direction of theplurality of burning plates are pressed to the inner sides in thearrangement direction by the reaction forces of the compression of thepacking between the outer edges on the outer sides in the arrangementdirection of the burning plates and the stepped portion. Consequently,the gas leakage from the butting parts of the burning plates can beprevented without using any spring members, and the number of parts canbe decreased to enable cost reduction.

Now, the open surface of the burner main body and each of the burningplates are generally formed in a square in plan view. In this case, ifthe corner parts formed by the end faces of the outer edges on the outersides in the arrangement direction of the burning plates situated onboth the outer sides in the arrangement direction of the plurality ofburning plates and the end faces of the outer edges parallel to thearrangement direction are angular, excess thickness parts of the packingproduced at the time of drawing the packing between the corner parts ofthe burning plates and the corner parts of the stepped part situated onthe outer side of the corner parts of the burning plates by pressing theburning plates downward gathers together on the under surfaces of thecorner parts of the burning plates to wrinkle, and the sealing propertyis deteriorated.

Accordingly, the corner parts of the burning plates situated on both theouter sides in the arrangement direction of the plurality of burningplates is preferably formed in chamfered shapes. The gap between thecorner parts of the burning plates and the corner parts of the steppedpart situated on the outer side of the corner parts of the burningplates consequently becomes wide, and the excess thickness parts of thepacking can be received in the gap. Consequently, the excess thicknessparts of the packing do not gather together and wrinkle on the undersurface of the corner parts of the burning plates, and good sealingproperty between the burner main body and the burning plates can besecured.

Moreover, in the present invention, it is preferable that a chamferedportion is formed on an upper edge of the stepped part. When the packingis drawn between the stepped part and the end face of the outer edge ofeach of the burning plates by pressing each of the burning platesdownward, it can consequently be prevented that the packing is caught bythe corner on the upper edge of the stepped part and is damaged.

Moreover, in the present invention, it is preferable that an adhesive iscoated on an under surface of the packing, and the packing is adhered toat least one of the inner part and the outer part of the flange portion.When the burning plates are set on the packing, the packing can therebybe prevented from being displaced, and the working property of theassembling of the burner is improved.

Advantages of the invention will be set forth in the description whichfollows, and in part will be obvious from the description, or may belearned by practice of the invention. Advantages of the invention may berealized and obtained by means of the instrumentalities and combinationsparticularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention, in which drawings:

FIGS. 1A, 1B, and 1C are sectional views showing the structure of theplate type burner of a first embodiment of the present invention and anassembly process thereof;

FIG. 2 is a plan view showing the burner main body of the plate typeburner of FIG. 1; and

FIG. 3 is a sectional view showing an exploded state of the plate typeburner of a second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described with reference tothe accompanying drawings.

With reference to FIGS. 1A-1C and 2, numeral 1 denotes a burner mainbody 1 of the plate type burner of a first embodiment. The burner mainbody 1 is a cast made of a metal, such as an aluminum alloy, and isformed in a box with the upper surface thereof shaped as an open surface1 a of a square in plan view. Two burning plates 2 each being square inplan view are mounted on the open surface 1 a by being arranged in thelateral direction. Each of the burning plates 2 is made of a ceramic,and a multiplicity of burner ports 2 a are formed therein. A mixture gas(mixture gas of a fuel gas and primary air) is supplied into the burnermain body 1 through a mixing tube unit (not illustrated), and themixture gas jets from the inner part of the burner main body 1 forcombustion through the burner ports 2 a of each of the burning plates 2.

A flange portion 3 enclosing the open surface 1 a is formed on the uppersurface of the burner main body 1. Then, the outer edge of each of theburning plates 2 is placed on the flange portion 3 with a square annularsheet of packing 4, made of “Kaowool” (trade name of ceramic fibersproduced by ISOLITE INSULATING PRODUCTS CO., LTD. of Japan) or the like,put between the outer edge and the flange portion 3, and the packing 4is compressed by pressing the outer edge of each of the burning plates 2with a square annular pressing plate 5 downward to secure the sealingproperty between the burner main body 1 and each of the burning plates2. Incidentally, although a sheet of packing punched into a squareannular shape can be used as the packing 4, two sheets of packingpunched in a letter L may be combined with each other to constitute thesquare annular sheet of packing 4. Moreover, another sheet of packing 6is provided between the butting parts of the burning plates 2.

The flange portion 3 is formed in a stepped shape in which the innerpart 3 a on the side of the open surface 1 a is lowered than the outerpart 3 b, and a stepped part 3 c shaped in the vertical direction isformed between the inner part 3 a and the outer part 3 b. Moreover, aplurality of screw holes 3 d is formed in the outer part 3 b.

The packing 4 is formed in a size to cover the screw holes 3 d in thestate of extending from the inner part 3 a of the flange portion 3 andexceeding the stepped part 3 c thereof to project to the outer part 3 bthereof. Moreover, through-holes 4 a are formed at the parts of thepacking 4 agreeing with the positions of the screw holes 3 d.

Through-holes are formed also at the positions in the pressing plate 5agreeing with those of the screw holes 3 d, and the pressing plate 5 isfastened to the flange portion 3 with screws 5 a screwed into the screwholes 3 d through the through-holes formed in the pressing plate 5 andthe through-holes 4 a of the packing 4. Moreover, a clamping plane 2 blower than the upper surface of the burner port forming region of eachof the burning plates 2 is formed by cutting work on the upper surfaceof the outer edge of each of the burning plates 2. Then, an engagingportion 5 b rising upward to engage with the clamping plane 2 b isformed in the inner edge part of the pressing plate 5, and the outeredge of each of the burning plates 2 is thereby pressed downward by theengaging portion 5 b at the time of fastening the pressing plate 5 tothe flange portion 3. Incidentally, the above configuration of formingthe clamping planes 2 b to be lower than the burner port forming regionsenables the engaging portion 5 b of the pressing plate 5 engaging theclamping plane 2 b to be distant from the flames produced on the burnerport forming regions. Thereby, the thermal deformation of the pressingplate 5 is suppressed to enable the pressing plate 5 to stably press theburning plates 2.

The stepped part 3 c of the flange portion 3 is here formed at positionswhere a gap “a” between the end face of the outer edge of each of theburning plates 2 and the stepped part 3 c is formed which gap “a” isnarrower than the thickness t of the packing 4 in the free statethereof. For example, if the thickness t of the packing 4 in the freestate thereof is 2 mm, the position of the stepped part 3 c is set inorder that the gap “a” between the end face of the outer edge of each ofthe burning plates 2 and the stepped part 3 c may be 1 mm.

Furthermore, a chamfered portion 3 e in an inclined surface is formed atthe upper edge of the stepped part 3 c. Moreover, as shown in FIG. 2,the corner parts 2 c formed by the end face of the outer edge on theouter side in the arrangement direction of each of the burning plates 2(left end face of the left side burning plate 2 and the right end faceof the right side burning plate 2) and the end faces of the outer edgesparallel to the arrangement direction of each of the burning plates 2are formed in chamfered shapes of inclined surfaces. Incidentally, thechamfered portion 3 e and the corner parts 2 c may be formed in roundedsurfaces.

At the time of assembly of the plate type burner, first, as shown inFIG. 1A, the packing 4 is placed on the flange portion 3, and next, asshown in FIG. 1B, the outer edge of each of the two burning plates 2 isplaced on the packing 4 with the packing 6 being provided between thebutting parts of the two burning plates 2. Lastly, as shown in FIG. 1C,the pressing plate 5 is fastened to the flange portion 3 to press theouter edge of each of the burning plates 2 downward.

At this time, the packing 4 is compressed between the inner part 3 a ofthe flange portion 3 and the under surface of the outer edge of each ofthe burning plates 2, and the packing 4 is compressed also in the gap“a” between the end face of the outer edge of each of the burning plate2 and the stepped part 3 c of the flange portion 3 because the gap “a”is narrower than the thickness t of the packing 4 in the free statethereof. The sealing property between the burner main body 1 and each ofthe burning plates 2 thus becomes good. Moreover, each of the burningplates 2 is pressed to the inner part in the arrangement direction bythe reaction force of the compression of the packing 4 between the endface of the outer edge on the outer side in the arrangement directionand the stepped part 3 c. Consequently, without using any spring memberspressing each of the burning plates 2 onto the inner side in thearrangement direction, the packing 6 provided between the butting partsof the burning plates 2 is sufficiently compressed, and gas leakage fromthe butting parts can be prevented. Consequently, no spring membersbecome necessary, and the number of the parts can be reduced to achievecost reduction.

Moreover, because the chamfered portion 3 e is formed at the upper edgeof the stepped part 3 c, it can be prevented that the packing 4 iscaught by the corner of the upper edge of the stepped part 3 c to bedamaged at the time of drawing the packing 4 into the gap “a” betweenthe stepped part 3 c and the end face of the outer edge of each of theburning plates 2 by pressing each of the burning plates 2 downward.

Furthermore, because the corner parts 2 c on the outer side in thearrangement direction of each of the burning plates 2 are formed inchamfered shapes, the gaps between the corner parts 2 c and the cornerparts 3 f of the stepped part 3 c which corner parts 3 f are situated onthe outer side of the corner parts 2 c become wide. Then, the excessthickness parts of the packing 4 produced along with the drawing of thepacking 4 into the corner parts 3 f of the stepped part 3 c are receivedin the gaps. Consequently, the excess thickness parts of the packing 4does not gather together to wrinkle on the under surface of the cornerparts 2 c of the burning plates 2. Thus, the sealing property betweenthe burner main body 1 and the burning plates 2 can be secured to begood.

Next, a second embodiment shown in FIG. 3 will be described. Althoughthe second embodiment is the same as the first embodiment in the basicstructure, the second embodiment is different from the first embodimentin the following point. That is, in the second embodiment, an adhesiveis coated on the under surface of the packing 4, and the packing 4 ispreviously adhered to the inner part 3 a and the outer part 3 b of theflange portion 3.

By this configuration, the positional displacement of the packing 4 atthe time of setting each of the burning plates 2 on the packing 4 can beprevented, and the workability of the assembling of the parts isimproved. Incidentally, the packing 4 may previously be adhered toeither the inner part 3 a or the outer part 3 b of the flange portion 3.

Although the embodiments of the present invention have been describedwith reference to the accompanying drawings, the present invention is nolimited to those embodiments. For example, in the embodiments, thenumber of the burning plates 2 is two, and the burning plates situatedon both the outer sides in the arrangement direction correspond to thesetwo burning plates 2. Consequently, the corner parts 2 c of each of theburning plates 2 on the outer sides in the arrangement direction areformed in the chamfered shapes. But, if three or more burning plates aremounted by being arranged on the open surface 1 a of the burner mainbody 1, the corner parts of only the two burning plates situated on boththe outer sides in the arrangement direction are formed in the chamferedshapes.

Moreover, although the upper surface of the burner main body 1 is formedas the open surface 1 a in the embodiments, the vertical direction doesnot regulate the directions of the burner at the time of its use, andthe present invention includes also the burners used in a downwardposture turning the burning plates 2 downward and a lateral postureturning the burning plates 2 into a lateral direction in addition to theburner used in the upward posture turning the burning plates 2 upward.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1. A plate type burner, comprising: a burner main body shaped in a boxwith an upper surface thereof being formed as an open surface; aplurality of burning plates mounted side by side in the open surface sothat a mixture gas is jetted for combustion from inside the burner mainbody through a multiplicity of burner ports formed in each of theburning plates; the burner main body having formed on the upper surfacethereof a flange portion in a manner to enclose the open surface, eachof the burning plates being placed on the flange portion at an outeredge thereof with an annular packing being interposed therebetween suchthat, by pressing downward the outer edge of each of the burning platesby a pressing plate to compress the packing, sealing property is securedbetween the burner main body and each of the burning plates, wherein theflange portion is formed in a stepped shape with an inner part on a sideof the open surface being lower than an outer part, wherein a verticalstepped part between the inner part and the outer part is formed at aposition where a gap narrower than a thickness of the packing in a freestate thereof is produced between an end face of the outer edge of eachof the burning plates and the stepped part; and wherein the packing isformed in a size large enough to project from the inner part of theflange portion to the outer part thereof beyond the stepped part.
 2. Theplate type burner according to claim 1, wherein the open surface andeach of the burning plates are formed in a square in plan view, andwherein corner parts formed by the end faces of the outer edges on outersides in an arrangement direction of the burning plates situated on boththe outer sides in the arrangement direction among the plurality ofburning plates and end faces of the outer edges parallel to thearrangement direction are formed in chamfered shapes.
 3. The plate typeburner according to claim 1, wherein a chamfered portion is formed on anupper edge of the stepped part.
 4. The plate type burner according toclaim 1, wherein an adhesive is coated on an under surface of thepacking, and wherein the packing is adhered to at least one of the innerpart and the outer part of the flange portion.